Evaluation of sex differences in the receipt of concomitant atrial fibrillation procedures during nonmitral cardiac surgery.

OBJECTIVE: Women are less likely to receive guideline-recommended cardiovascular care, but evaluation of sex-based disparities in cardiac surgical procedures is limited. Receipt of concomitant atrial fibrillation (AF) procedures during nonmitral cardiac surgery was compared by sex for patients with preoperative AF. METHODS: Patients with preoperative AF undergoing coronary artery bypass grafting and/or aortic valve replacement at any of the 33 hospitals in Michigan from 2014 to 2022 were included. Patients with prior cardiac surgery, transcatheter AF procedure, or emergency/salvage status were excluded. Hierarchical logistic regression identified predictors of concomitant AF procedures, account for hospital and surgeon as random effects. RESULTS: Of 5460 patients with preoperative AF undergoing nonmitral cardiac surgery, 24% (n = 1291) were women with a mean age of 71 years. Women were more likely to have paroxysmal (vs persistent) AF than men (80% vs 72%; P < .001) and had a higher mean predicted risk of mortality (5% vs 3%; P < .001). The unadjusted rate of concomitant AF procedure was 59% for women and 67% for men (P < .001). After risk adjustment, women had 26% lower adjusted odds of concomitant AF procedure than men (adjusted odds ratio, 0.74; 95% CI, 0.64-0.86; P < .001). Female sex was the risk factor associated with the lowest odds of concomitant AF procedure. CONCLUSIONS: Women are less likely to receive guideline recommended concomitant AF procedure during nonmitral surgery. Identification of barriers to concomitant AF procedure in women may improve treatment of AF.

Interhospital variability in cardiac rehabilitation use after cardiac surgery among Medicare beneficiaries.

OBJECTIVE: Despite guideline recommendation, cardiac rehabilitation (CR) after cardiac surgery remains underused, and the extent of interhospital variability is not well understood. This study evaluated determinants of interhospital variability in CR use and outcomes. METHODS: This retrospective cohort study included 166,809 Medicare beneficiaries undergoing cardiac surgery who were discharged alive between July 1, 2016, and December 31, 2018. CR participation was identified in outpatient facility claims within a year of discharge. Hospital-level CR rates were tabulated, and multilevel models evaluated the extent to which patient, organizational, and regional factors accounted for interhospital variability. Adjusted 1-year mortality and readmission rates were also calculated for each hospital quartile of CR use. RESULTS: Overall, 90,171 (54.1%) participated in at least 1 CR session within a year of discharge. Interhospital CR rates ranged from 0.0% to 96.8%. Hospital factors that predicted CR use included nonteaching status and lower-hospital volume. Before adjustment for patient, organizational, and regional factors, 19.3% of interhospital variability was attributable to the admitting hospital. After accounting for covariates, 12.3% of variation was attributable to the admitting hospital. Patient (0.5%), structural (2.8%), and regional (3.7%) factors accounted for the remaining explained variation. Hospitals in the lowest quartile of CR use had greater adjusted 1-year mortality rates (Q1 = 6.7%, Q4 = 5.2%, P < .001) and readmission rates (Q1 = 37.6%, Q4 = 33.9%, P < .001). CONCLUSIONS: Identifying best practices among high CR use facilities and barriers to access in low CR use hospitals may reduce interhospital variability in CR use and advance national improvement efforts.

Sex-Based Differences in Concomitant Tricuspid Repair During Degenerative Mitral Surgery.

BACKGROUND: Women with mitral valve disease have higher rates of tricuspid regurgitation (TR) than men. Although tricuspid valve repair (TVr) decreases the progression of TR, we hypothesize that there may be sex-based differences in concomitant TVr at the time of mitral valve operations. METHODS: Adults undergoing mitral valve operation for degenerative disease with moderate or worse preoperative TR at a high-volume center from 2014 to 2023 were identified. Patients with a previous tricuspid intervention were excluded. A multivariable logistic regression identified predictors of concomitant TVr. To evaluate the clinical impact of not performing TVr, a competing risk model compared development of severe TR or valve-related reoperation by sex among patients without TVr. RESULTS: Most included patients were women (55% [n = 214 of 388]), and the median age was 73 years (quartile 1-quartile 3, 65-79 years). There was no difference in the rate of severe TR by sex (female, 28%; male, 26%; P = .63). The unadjusted rate of concomitant TVr was 57% for women and 73% for men (P < .001). Overall, women had 52% lower adjusted odds of TVr (adjusted odds ratio, 0.48; 95% CI, 0.29-0.81; P = .006), including a lower adjusted rate for moderate TR (47% [95% CI, 45%-49%] vs 66% [95% CI, 64%-69%]) and for severe TR (83% [95% CI, 81%-86] vs 92% [95% CI, 90%-93%]) Among those without TVr, 12% of women and 0% of men had severe TR or required a valve-related reoperation at 4 years (P < .001). CONCLUSIONS: Women with moderate or severe TR undergoing mitral valve operation for degenerative disease were less likely to receive concomitant TVr, severe TR was more likely to develop, or they would more likely need a valve-related reoperation. Evaluation of sex-based treatment differences is imperative to improve outcomes for women.

The relationship between discharge location and cardiac rehabilitation use after cardiac surgery.

BACKGROUND: Cardiac rehabilitation (CR) is a guideline-recommended risk-reduction program offered to cardiac surgical patients. Despite CR's association with better outcomes, attendance remains poor. The relationship between discharge location and CR use is poorly understood. METHODS: This study was a nationwide, retrospective cohort analysis of Medicare fee-for-service claims for beneficiaries undergoing coronary artery bypass grafting and/or surgical aortic valve repair between July 1, 2016, and December 31, 2018. The primary outcome was attendance of any CR session. Discharge location was categorized as home discharge or discharge to extended care facility (ECF) (including skilled nursing facility, inpatient rehabilitation, and long-term acute care). Multivariable logistic regression models evaluated the association between discharge location, CR attendance, and 1-year mortality. RESULTS: Of the 167,966 patients who met inclusion criteria, 34.1% discharged to an ECF. Overall CR usage rate was 53.9%. Unadjusted and adjusted CR use was lower among patients discharged ECFs versus those discharged home (42.1% vs 60.0%; adjusted odds ratio, 0.66; P < .001). Patients discharged to long-term acute care were less likely to use CR than those discharged to skilled nursing facility or inpatient rehabilitation (reference category: home; adjusted odds ratio for long-term acute care, 0.36, adjusted odds ratio for skilled nursing facility, 0.69, and adjusted odds ratio for inpatient rehabilitation, 0.71; P < .001). CR attendance was associated with a greater reduction in adjusted 1-year mortality in patients discharged to ECFs (9.7% reduction) versus those discharged home (4.3% reduction). CONCLUSIONS: In this national analysis of Medicare beneficiaries, discharge to ECF was associated with lower CR use, despite a greater association with improved 1-year mortality. Interventions aimed at increasing CR enrollment at ECFs may improve CR use and advance surgical quality.

Advancing cardiotomy suction practices for coronary surgery via multidisciplinary collaborative learning.

Objective: Professional standards recommend stopping cardiotomy suction at the termination of cardiopulmonary bypass before protamine administration based on perceived safety concerns. This study evaluated a multidisciplinary collaborative quality-improvement intervention promoting this agreed-upon cardiotomy suction practice during coronary artery bypass grafting (CABG). Methods: A statewide intervention (eg, unblinded surgeon and perfusionist feedback, evidence-based lectures, evaluating barriers to change) involved 32 centers participating in the PERForm (ie, Perfusion Measures and Outcomes) Registry to standardize cardiotomy suction practices at cardiopulmonary bypass termination during CABG. Four non-Michigan registry participating centers were not exposed to collaborative learning. Cardiotomy suction practice was defined as the absence of or stopping cardiotomy suction before protamine administration. The practice changes attributed to the intervention, including Michigan and non-Michigan comparisons, were evaluated with the change of time effect modeled using splines. Multivariable regression was used to evaluate the intervention's associated impact (eg, mortality, reoperation, transfusion). Results: Among 10,394 patients undergoing CABG at Michigan centers, 80.7% achieved agreed-upon cardiotomy suction practices. The Michigan centers had nonsignificant changes in agreed-upon cardiotomy suction practices during the preintervention period (P = .24), with significant increased monthly change in practice thereafter, absent adjusted morbidity and mortality increases. The Michigan centers achieved a significantly greater adjusted monthly improvement in agreed-upon practices relative to non-Michigan centers within 7 months after the intervention (adjusted odds ratio for change of trends: 2.53, P < .001). Conclusions: This initiative demonstrates the effectiveness of multidisciplinary collaborative quality improvement in advancing agreed-upon cardiotomy suction practices without negatively impacting clinical outcomes.

Hospital Variation in Skilled Nursing Facility Use After Coronary Artery Bypass Graft Surgery.

BACKGROUND: Over 20% of patients are discharged to a skilled nursing facility (SNF) after coronary artery bypass graft surgery, but little is known about specific drivers for postdischarge SNF use. The purpose of this study was to evaluate hospital variation in SNF use and its association with postoperative outcomes after coronary artery bypass graft. METHODS AND RESULTS: A retrospective study design utilizing Medicare Provider Analysis and Review files was used to evaluate SNF use among 70 509 beneficiaries undergoing coronary artery bypass graft, with or without valve procedures, between 2016 and 2018. A total of 17 328 (24.6%) were discharged to a SNF, ranging from 0% to 88% across 871 hospitals. Multilevel logistic regression models identified significant patient-level predictors of discharge to SNF including increasing age, comorbidities, female sex, Black race, dual eligibility, and postoperative complications. After adjusting for patient and hospital factors, 15.6% of the variation in hospital SNF use was attributed to the discharging hospital. Compared with the lower quartile of hospital SNF use, hospitals in the top quartile of SNF use had lower risk-adjusted 1-year mortality (12.5% versus 8.6%, P<0.001) and readmission (59.9% versus 49.8%, P<0.001) rates for patients discharged to a SNF. CONCLUSIONS: There is high variability in SNF use among hospitals that is only partially explained by patient characteristics. Hospitals with higher SNF utilization had lower risk-adjusted 1-year mortality and readmission rates for patients discharged to a SNF. More work is needed to better understand underlying provider and hospital-level factors contributing to SNF use variability.

A Nationwide Evaluation of Cardiothoracic Resident Research Productivity.

BACKGROUND: Evaluating the research productivity of cardiothoracic surgery residents during their training and early career is crucial for tracking their academic development. To this end, the training pathway of residents and the characteristics of their program in relation to their productivity were evaluated. METHODS: Alumni lists from integrated 6-year thoracic surgery (I-6) and traditional thoracic surgery residency programs were collected. A Python script was used to search PubMed for publications and the iCite database for citations from each trainee. Publications during a 20-year time span were stratified by the year of publication in relation to the trainee's graduation from thoracic surgery residency. Trainees were analyzed by training program type, institutional availability of a cardiothoracic surgery T32 training grant, and protected academic development time. RESULTS: A total of 741 cardiothoracic surgery graduates (I-6, 70; traditional, 671) spanning 1971 to 2021 from 57 programs published >23,000 manuscripts. I-6 trainees published significantly more manuscripts during medical school and residency compared with traditional trainees. Trainees at institutions with cardiothoracic surgery T32 training grants published significantly more manuscripts than those at non-T32 institutions (13 vs 9; P = .0048). I-6 trainees published more manuscripts at programs with dedicated academic development time compared with trainees at programs without protected time (22 vs 9; P = .004). CONCLUSIONS: I-6 trainees publish significantly more manuscripts during medical school and residency compared with their traditional colleagues. Trainees at institutions with T32 training grants and dedicated academic development time publish a higher number of manuscripts than trainees without those opportunities.

Evaluating the Impact of Operative Team Familiarity on Cardiac Surgery Outcomes: A Retrospective Cohort Study of Medicare Beneficiaries.

OBJECTIVE: To associate surgeon-anesthesiologist team familiarity (TF) with cardiac surgery outcomes. BACKGROUND: TF, a measure of repeated team member collaborations, has been associated with improved operative efficiency; however, examination of its relationship to clinical outcomes has been limited. METHODS: This retrospective cohort study included Medicare beneficiaries undergoing coronary artery bypass grafting (CABG), surgical aortic valve replacement (SAVR), or both (CABG+SAVR) between January 1, 2017, and September 30, 2018. TF was defined as the number of shared procedures between the cardiac surgeon and anesthesiologist within 6 months of each operation. Primary outcomes were 30- and 90-day mortality, composite morbidity, and 30-day mortality or composite morbidity, assessed before and after risk adjustment using multivariable logistic regression. RESULTS: The cohort included 113,020 patients (84,397 CABG; 15,939 SAVR; 12,684 CABG+SAVR). Surgeon-anesthesiologist dyads in the highest [31631 patients, TF median (interquartile range)=8 (6, 11)] and lowest [44,307 patients, TF=0 (0, 1)] TF terciles were termed familiar and unfamiliar, respectively. The rates of observed outcomes were lower among familiar versus unfamiliar teams: 30-day mortality (2.8% vs 3.1%, P =0.001), 90-day mortality (4.2% vs 4.5%, P =0.023), composite morbidity (57.4% vs 60.6%, P <0.001), and 30-day mortality or composite morbidity (57.9% vs 61.1%, P <0.001). Familiar teams had lower overall risk-adjusted odds of 30-day mortality or composite morbidity [adjusted odds ratio (aOR) 0.894 (0.868, 0.922), P <0.001], and for SAVR significantly lower 30-day mortality [aOR 0.724 (0.547, 0.959), P =0.024], 90-day mortality [aOR 0.779 (0.620, 0.978), P =0.031], and 30-day mortality or composite morbidity [aOR 0.856 (0.791, 0.927), P <0.001]. CONCLUSIONS: Given its relationship with improved 30-day cardiac surgical outcomes, increasing TF should be considered among strategies to advance patient outcomes.

Modeling and estimating a threshold effect: An application to improving cardiac surgery practices.

Estimating thresholds when a threshold effect exists has important applications in biomedical research. However, models/methods commonly used in the biomedical literature may lead to a biased estimate. For patients undergoing coronary artery bypass grafting (CABG), it is thought that exposure to low oxygen delivery (DO2) contributes to an increased risk of avoidable acute kidney injury. This research is motivated by estimating the threshold of nadir DO2 for CABG patients to help develop an evidence-based guideline for improving cardiac surgery practices. We review several models (sudden-jump model, broken-stick model, and the constrained broken-stick model) that can be adopted to estimate the threshold and discuss modeling assumptions, scientific plausibility, and implications in estimating the threshold. Under each model, various estimation methods are studied and compared. In particular, under a constrained broken-stick model, a modified two-step Newton-Raphson algorithm is introduced. Through comprehensive simulation studies and an application to data on CABG patients from the University of Michigan, we show that the constrained broken-stick model is flexible, more robust, and able to incorporate scientific knowledge to improve efficiency. The two-step Newton-Raphson algorithm has good computational performances relative to existing methods.

del Nido versus blood cardioplegia in cardiac surgery: A multicenter analysis of over 40,000 patients.

OBJECTIVES: The use of del Nido cardioplegia in adult cardiac surgery is rising in popularity. The objective of this large multicenter study was to evaluate the use and associated outcomes of del Nido versus blood cardioplegia in adult cardiac surgery. METHODS: Patients undergoing coronary artery bypass grafting (CABG) and/or valve (mitral, aortic), and/or nondescending thoracic aortic surgery (July 2014 to March 2022) across 39 centers were extracted from the Perfusion Measures and Outcomes registry. Patients were stratified by cardioplegia type for unadjusted analysis and multivariable mixed-effects models were used for risk adjustment. RESULTS: Of 44,175 patients, 42.5% used del Nido, with use increasing 48% over time. Overall, the del Nido group had shorter median crossclamp time (74 minutes vs 87 minutes, P < .001) and lower median peak intraoperative glucose levels (161 mg/dL vs 180 mg/dL, P < .001). Use of del Nido was not associated with operative mortality (adjusted odds ratio [ORadj], 1.16; P = .075) nor major morbidity (ORadj, 1.05; P = .25). Findings for valve cases were similar, except crossclamp time differences were variable by type of valve procedure. Within the CABG subgroup there was a trend toward increased operative mortality with del Nido (ORadj, 1.24; P = .069), whereas the risk of renal failure approaches statistical significance in the aortic subgroup (ORadj, 1.54; P = .056). CONCLUSIONS: In this large, multicenter study, the use of del Nido was associated with variable crossclamp time differences, lower intraoperative glucose levels, and no significant difference in major morbidity or mortality. Efficiency benefits of del Nido may be limited in valve cases, whereas outcomes in CABG and aortic cases warrant further study.

The association of intraoperative and early postoperative events with risk of pneumonia following cardiac surgery.

BACKGROUND: Pneumonia, the most common infection following cardiac surgery, is associated with major morbidity and mortality. Although prior work has identified preoperative risk factors for pneumonia, the present study evaluated the role and associated impact of intraoperative and postoperative risk factors on pneumonia after cardiac surgery. METHODS: This observational cohort study evaluated 71,165 patients undergoing coronary and/or aortic valve surgery across 33 institutions between 2011 and 2021. Terciles of estimated pneumonia risk were compared between a validated preoperative model (Model One) and a model additionally accounting for significant intraoperative (eg, bypass duration) and postoperative (eg, extubation time) factors (Model Two). Logistic regression was used to develop and validate Model Two. RESULTS: Postoperative pneumonia occurred in 2.62% of the patients. A total of 9 significant intraoperative and early postoperative risk factors were identified. The absolute risk of pneumonia increased across Model One terciles: low (≤1.04%), medium (1.04%-2.40%), and high (>2.40%). Model two performed well (c-statistic = 0.771). Most patients (60.1%) had no change in their preoperative versus intraoperative/postoperative risk tercile. The 19.6% of patients who increased their risk tercile with Model Two accounted for 18.6% of all pneumonia events. CONCLUSIONS: This study identified 9 significant perioperative risk factors for pneumonia. Nearly 1 of every 5 patients moved into a higher pneumonia risk category based on their intraoperative and postoperative course. These findings may serve as the focus of future quality improvement efforts to reduce a patient's risk of postoperative pneumonia.

Determinants and Outcomes Associated With Skilled Nursing Facility Use After Coronary Artery Bypass Grafting: A Statewide Experience.

BACKGROUND: Skilled nursing facility (SNF) care is frequently used after cardiac surgery, but the patterns and determinants of use have not been well understood. The objective of this study was to evaluate determinants and outcomes associated with SNF use after isolated coronary artery bypass grafting. METHODS: A retrospective analysis of Medicare Fee-For-Service claims linked to the Society of Thoracic Surgeons clinical data was conducted on isolated coronary artery bypass grafting patients without prior SNF use in Michigan between 2011 and 2019. Descriptive analysis evaluated the frequency, trends, and variation in SNF use across 33 Michigan hospitals. Multivariable mixed-effects regression was used to evaluate patient-level demographic and clinical determinants of SNF use and its effect on short- and long-term outcomes. RESULTS: In our sample of 8614 patients, the average age was 73.3 years, 70.5% were male, and 7.7% were listed as non-White race. An SNF was utilized by 1920 (22.3%) patients within 90 days of discharge and varied from 3.2% to 58.3% across the 33 hospitals. Patients using SNFs were more likely to be female, older, non-White, with more comorbidities, worse cardiovascular function, a perioperative morbidity, and longer hospital lengths of stay. Outcomes were significantly worse for SNF users, including more frequent 90-day readmissions and emergency department visits and less use of home health and rehabilitation services. SNF users had higher risk-adjusted hazard of mortality (hazard ratio, 1.41 [95% CI, 1.26-1.57]; P<0.001) compared with non-SNF users and had 2.7-percentage point higher 5-year mortality rate in a propensity-matched cohort of patients (18.1% versus 15.4%; P<0.001). CONCLUSIONS: The use of SNF care after isolated coronary artery bypass grafting was frequent and variable across Michigan hospitals and associated with worse risk-adjusted outcomes. Standardization of criteria for SNF use may reduce variability among hospitals and ensure appropriateness of use.

Preoperative passive venous pressure-driven cardiac function determines left ventricular assist device outcomes.

BACKGROUND: Right heart output in heart failure can be compensated through increasing systemic venous pressure. We determined whether the magnitude of this "passive cardiac output" can predict LVAD outcomes. METHODS: This was a retrospective review of 383 patients who received a continuous-flow LVAD at the University of Michigan between 2012 and 2021. Pre-LVAD cardiac output driven by venous pressure was determined by dividing right atrial pressure by mean pulmonary artery pressure, multiplied by total cardiac output. Normalization to body surface area led to the passive cardiac index (PasCI). The Youden J statistic was used to identify the PasCI threshold, which predicted LVAD death by 2 years. RESULTS: Increased preoperative PasCI was associated with reduced survival (hazard ratio [HR], 2.27; P < .01), and increased risk of right ventricular failure (RVF) (HR, 3.46; P = .04). Youden analysis showed that a preoperative PasCI ≥0.5 (n = 226) predicted LVAD death (P = .10). Patients with PasCI ≥0.5 had poorer survival (P = .02), with a trend toward more heart failure readmission days (mean, 45.09 ± 67.64 vs 35.13 ± 45.02 days; P = .084) and increased gastrointestinal bleeding (29.2% vs 20.4%; P = .052). Additionally, of the 97 patients who experienced readmissions for heart failure, those with pre-LVAD implantation PasCI ≥0.5 were more likely to have more than 1 readmission (P = .05). CONCLUSIONS: Although right heart output can be augmented by raising venous pressure, this negatively impacts end-organ function and increases heart failure readmission days. Patients with a pre-LVAD PasCI ≥0.5 have worse post-LVAD survival and increased RVF. Using the PasCI metric in isolation or incorporated into a predictive model may improve the management of LVAD candidates with RV dysfunction.

Cardiac Rehabilitation Reduces 2-Year Mortality After Coronary Artery Bypass Grafting.

BACKGROUND: Cardiac rehabilitation (CR) is a supervised outpatient exercise and risk reduction program offered to patients who have undergone coronary revascularization procedures. Multiple professional societal guidelines support the use of CR after coronary artery bypass grafting (CABG) based on studies in combined percutaneous coronary intervention and CABG populations with surrogate outcomes. This statewide analysis of patients undergoing CABG evaluated the relationship between CR use and long-term mortality. METHODS: Medicare fee-for-service claims were linked to surgical data for patients discharged alive after isolated CABG from January 1, 2015, through September 30, 2019. Outpatient facility claims were used to identify any CR use within 1 year of discharge. Death within 2 years of discharge was the primary outcome. Mixed-effects logistic regression was used to predict CR use, adjusting for a variety of comorbidities. Unadjusted and inverse probability treatment weighting (IPTW) were used to compare 2-year mortality among CR users vs nonusers. RESULTS: A total of 3848 of 6412 patients (60.0%) were enrolled in CR for an average of 23.2 (SD, 12.0) sessions, with 770 of 6412 (12.0%) completing all recommended 36 sessions. Logistic regression identified increasing age, discharge to home (vs extended care facility), and shorter length of stay as predictors of postdischarge CR use (P < .05). Unadjusted and IPTW analyses showed significant reduction in 2-year mortality in CR users compared with CR nonusers (unadjusted: 9.4% reduction; 95% CI, 10.8%-7.9%; P < .001; IPTW: -4.8% reduction; 95% CI, 6.0%-3.5%; P < .001). CONCLUSIONS: These data suggest that CR use is associated with lower 2-year mortality. Future quality initiatives should consider identifying and addressing root causes of poor CR enrollment and completion.

Oxygen Delivery Thresholds During Cardiopulmonary Bypass and Risk for Acute Kidney Injury.

BACKGROUND: Postoperative acute kidney injury (AKI) in cardiac surgery patients is multifactorial and associated with low oxygen delivery (DO2) during cardiopulmonary bypass. METHODS: Cardiac surgical patients undergoing full cardiopulmonary bypass between May 1, 2016 and December 31, 2021 were included, whereas those on preoperative dialysis, undergoing circulatory arrest procedures, or lacking minute-to-minute physiologic data were excluded. A 5-minute running average of indexed DO2 (DO2i, mL/min/m2) was calculated ([pump flow] × [hemoglobin] × 1.36 [hemoglobin saturation] + 0.003 [arterial oxygen tension]/body surface area). AKI was defined using established Kidney Disease: Improving Global Outcomes criteria. The threshold of nadir DO2i on the effect of AKI was estimated using risk-adjusted Constrained Broken-Stick models. RESULTS: Postoperative AKI occurred among 1155 patients (29.4%), with 276 (7.0%) having stage 2 to 3 AKI. The median nadir DO2i was lower for those with (vs without) AKI (197.9 mL/min/m2 [interquartile range {IQR}, 166.3-233.2] vs 217.2 mL/min/m2 [IQR, 184.5-252.2], P < .001) and stage 2 to 3 AKI relative to stage 1 or none (186.9 mL/min/m2 [IQR, 160.1-220.5] vs 213.8 mL/min/m2 [IQR, 180.4-249.4]). In risk-adjusted analyses the estimated threshold for nadir DO2i was 231.2 mL/min/m2 (95% CI, 173.6-288.8) for any AKI and 103.3 (95% CI, 68.4-138.3) for stage 2 to 3 AKI. CONCLUSIONS: Decreasing nadir DO2i was associated with an increased risk of AKI. The identified nadir DO2i thresholds suggest management and treatment of nadir DO2i during cardiopulmonary bypass may decrease a patient's postoperative AKI risk.

Racial and ethnic disparities in diagnosis, management and outcomes of aortic stenosis in the Medicare population.

IMPORTANCE: Aortic stenosis (AS) is one of the most common heart valve conditions and its incidence and prevalence increases with age. With the introduction of transcatheter aortic valve replacement (TAVR), racial and ethnic disparities in AS diagnosis, treatment and outcomes is poorly understood. OBJECTIVE: In this study we assessed racial and ethnic disparities in AS diagnosis, treatment, and outcomes among Medicare beneficiaries. DESIGN: We conducted a population-based cohort study of inpatient, outpatient, and professional claims from a 20% sample of Medicare beneficiaries. MAIN OUTCOMES AND MEASURES: Incidence and Prevalence was determined among Medicare Beneficiaries. Outcomes in this study included management; the number of (non)-interventional cardiology and cardiothoracic surgery evaluation and management (E&M) visits, and number of transthoracic echocardiograms (TTE) performed. Treatment, which was defined as Surgical Aortic Valve Replacement and Transthoracic Aortic Valve Replacement. And outcomes described as All-cause Hospitalizations, Heart Failure Hospitalization and 1-year mortality. RESULTS: A total of 1,513,455 Medicare beneficiaries were diagnosed with AS (91.3% White, 4.5% Black, 1.1% Hispanic, 3.1% Asian and North American Native) between 2010 and 2018. Annual prevalence of AS diagnosis was lower for racial and ethnic minorities compared with White patients, with adjusted rate ratios of 0.66 (95% CI 0.65 to 0.68) for Black patients, 0.67 (95% CI 0.64 to 0.70) for Hispanic patients and 0.75 (95% CI 0.73 to 0.77) for Asian and North American Native patients as recent as 2018. After adjusting for age, sex and comorbidities, cardiothoracic surgery E&M visits and treatment rates were significantly lower for Black, Hispanic and Asian and North American Native patients compared with White patients. All-cause hospitalization rate was higher for Black and Hispanic patients compared with White patient. 1-year mortality was higher for Black patients, while Hispanic and Asian and North American Native patients had lower 1-year mortality compared with White patients. CONCLUSIONS AND RELEVANCE: We demonstrated significant racial and ethnic disparities in the diagnosis, management and outcomes of AS. The factors driving the persistence of these disparities in AS care need to be elucidated to develop an equitable health care system.

Association of Days Alive and Out of the Hospital After Ventricular Assist Device Implantation With Adverse Events and Quality of Life.

Importance: There is a need to better assess the cumulative effect on morbidity and mortality in patients undergoing durable left ventricular assist device (LVAD) implantation. This study evaluates a patient-centered performance metric (days alive and out of hospital [DAOH]) for durable LVAD therapy. Objective: To determine the incidence of percent of DAOH before and after LVAD implantation and (2) explore its association with established quality metrics (death, adverse events [AEs], quality of life). Design, Settings, and Participants: This was a retrospective national cohort study of Medicare beneficiaries implanted with a durable continuous-flow LVAD between April 2012 and December 2016. The data were analyzed from December 2021 to May 2022. Follow-up was 100% complete at 1 year. Data from The Society of Thoracic Surgeons Intermacs registry were linked to Medicare claims. Main Outcomes and Measures: The number of DAOH 180 days before and 365 days after LVAD implantation and daily patient location (home, index hospital, nonindex hospital, skilled nursing facility, rehabilitation center, hospice) were calculated. Percent of DAOH was indexed to each beneficiary's pre- (percent DAOH-BF) and postimplantation (percentage of DAOH-AF) follow-up time. The cohort was stratified by terciles of percentage of DAOH-AF. Results: Among the 3387 patients included (median [IQR] age: 66.3 [57.9-70.9] years), 80.9% were male, 33.6% and 37.1% were Interfaces Patient Profile 2 and 3, respectively, and 61.1% received implants as destination therapy. Median (IQR) percent of DAOH-BF was 88.8% (82.7%-93.8%) and 84.6% (62.1-91.5%) for percent of DAOH-AF. While DAOH-BF was not associated with post-LVAD outcomes, patients in the low tercile of percentage of DAOH-AF had a longer index hospitalization stay (mean, 44 days; 95% CI, 16-77), were less likely to be discharged home (mean. -46.4 days; 95% CI, 44.2-49.1), and spent more time in a skilled nursing facility (mean, 27 days; 95% CI, 24-29), rehabilitation center (mean, 10 days; 95% CI, 8-12), or hospice (mean, 6 days; 95% CI, 4-8). Increasing percentage of DAOH-AF was associated with patient risk, AEs, and indices of HRQoL. Patients experiencing non-LVAD-related AEs had the lowest percentage of DAOH-AF. Conclusions and Relevance: Significant variability existed in the percentage of DAOH within a 1-year time horizon and was associated with the cumulative AEs burden. This patient-centered measure may assist clinicians in informing patients about expectations after durable LVAD implantation. Validation of percentage DAOH as a quality metric for LVAD therapy across centers should be explored.

Failure to rescue: A candidate quality metric for durable left ventricular assist device implantation.

OBJECTIVE: Failure to rescue (FTR), defined as death after a complication, is recognized as a principal driver of variation in mortality among hospitals. We evaluated FTR as a quality metric in patients who received durable left ventricular assist devices (LVADs) using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support. METHODS: Data on 13,617 patients who received primary durable LVADs from April 2012 to October 2017 at 131 hospitals that performed at least 20 implants were analyzed from the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support. Rates of major complications and FTR were compared across risk-adjusted in-hospital mortality terciles (low, medium, high) and hospital volume. Logistic regression was used to estimate expected FTR rates on the basis of patient factors for each major complication. RESULTS: The overall unadjusted in-hospital mortality rate was 6.96%. Risk-adjusted in-hospital mortality rates varied 3.1-fold across terciles (low, 3.3%; high, 10.3%; P trend <.001). Rates of major complications varied 1.1-fold (low, 34.0%; high, 38.8%; P < .0001). Among patients with a major complication, 854 died in-hospital for an FTR rate of 17.7%, with 2.8-fold variation across mortality terciles (low, 8.5%; high, 23.9%; P < .0001). FTR rates were highest for renal dysfunction requiring dialysis (45.3%) and stroke (36.5%). Higher average annual LVAD volume was associated with higher rates of major complications (<10 per year, 26.7%; 10-20 per year, 34.0%; 20-30 per year, 34.0%; >30 per year, 40.1%; P trend <.0001) whereas hospitals implanting <10 per year had the highest FTR rate (<10 per year, 23.5%; 10-20 per year, 16.5%; 20-30 per year, 17.0%; >30 per year, 17.9%; P = .03). CONCLUSIONS: FTR might serve as an important quality metric for durable LVAD implant procedures, and identifying strategies for successful rescue after complications might reduce hospital variations in mortality.